Piston for hydraulic cylinders



Swt W, 1935.

. T. F. SPICKNALL PISTON FOR HYDRAULIC CYLINDERS Filed Jan. 25, 1934 Patented Sept. 17, 1935 UNITED STATES PATENT OFFIQE 1 Claim.

My invention relates to improvements in pistons for hydraulic cylinders, and has for its object to provide a piston which is simple in construction, accurate in operation, and in which the parts can be readily replaced when worn.

The invention consists of the novel construction and arrangement of the parts and combination of parts hereinafter more fully set forth in the following specification and pointed out in detail in the appended claim.

In the accompanying drawing,-

Figure l is an endplan view.

Figure 2 is a section on the line 22 of Figure 1.

Figure 3 is a side elevation of Figure 1.

Figure 4 is an enlarged detail section taken through one of the ports of the piston casing.

Referring to the accompanying drawing, forming part of this specification, and in which like reference numerals designate like parts throughout the several views thereof, I designates the two piston castings over the ends of each of which is fitted a leather cup 2 and between the said two cups 2 on the piston castings I, is a steel spacer disk 3, said parts being securely held together by the bolts 4, each of which latter is provided with a lock washer 5. The spacer disk 3 is held in position on the shaft l by the hexagonshaped nuts 6, one on each side of said plate 3, and these nuts 6 each fits into a hexagon shaped recess 8 in the face of the piston castings I. The said piston castings I each have their inner ends contracted over which the leather cups 2 project so that the outer surfaces of the flanges of said cups 2 will be flush with the outer edges of the piston castings I. The outer edges of the piston castings I and cups 2 impinge against the inner surface of the piston chamber when in operation therein. The said contracted ends of the piston castings I are each provided with an annular groove 9 and the outer surfaces of said castings E are each provided with a number of ports it each communicating with the annular groove 9 so that the water rushing into the piston cylinder will pass through said ports Ill and into the groove 9 against the flanged edge of the leather cups 2 and hold the latter against the wall of the cylinder and prevent water from passing between the piston and the cylinder wall.

To assemble the parts one of the castings I is placed in the piston shaft 7 and one of the nuts 8 screwed upon the shaft I to the desired posi- 5 tion, one of the cups 2 is then placed over the contracted end of the casting I and the spacer plate 3 placed on the shaft I against the leather cup 2, and the other nut 6 is then screwed upon the shaft 7 against the spacer plate 3. The other 1 leather cup 2 is then placed over the contracted end of the other casting I and the latter placed on the shaft I with the hexagon-shaped nut 6 projecting into the hexagon-shaped recess 8. The parts are then securely fastened together with the bolts i. The hexagon-shaped nuts 6 projecting into the hexagon-shaped recesses 8 will prevent the parts turning on the shaft 1.

It will thus be seen that from whatever side the piston is operated the water will pass through the ports it to the annular groove 9 and force the flange of the leather cup 2 against the side of the piston chamber and prevent the water from passing between the piston and cylinder in which it is operating.

Having thus described my invention, what I claim is f A piston for hydraulic cylinders, comprising a shaft, two castings each having a central opening for said shaft and a recess in its inner face surrounding said shaft opening and having a portion of its outer edge contracted and provided with an annular groove and a number of ports in its outer surface leading to and communicating with said annular groove, a leather cup fitted on the contracted outer face of each of said castings and each having its flange projecting over the contracted outer portion of the casting and its outer surface flush with the outer surface of the casting and covering the entire annular groove in the contracted portion of the casting, a spacer plate between the two leather cups, and a nut on each side of the said spacer plate to hold it in position on the shaft and each nut projecting into the central recess in the adjoining casting.

THOMAS F. SPICKNALL. 

